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I need help with Launch Controls (WASDQE)


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Just now, Reactordrone said:

Struts are the EAS-4 strut connector. If you haven't unlocked them yet it doesn't matter but they're something to keep in mind for later builds. Only 1 set of radial decouplers can attach to a booster due to the tree structure construction in KSP  so there's not much point adding a second set.

I haven't unlocked the struts yet then.

And from what I've experienced, using the Hexagonal snapping and lining them up to be in a straight line allows for sturdier builds. Like if I wanted to attach a large booster, or a set of fuel tanks attached to an engine, and I used multiple radial decouplers aligned in a straight line, it stabilized previously unstable long rockets.

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9 hours ago, bewing said:

BTW -- I have to disagree with :

The air does not flow prograde around Kerbin. It is stationary above the surface. The only way to not go at an angle to the airflow is to go straight up. Steering or turning is what puts you at an angle to the airflow. You gain other efficiencies, but your drag increases when you go prograde in orbital mode.

Um, precisely. The air is stationary with respect to the "surface mode" reference frame. If you go straight up to 40km and then turn east, you are turning your rocket sideways to the airflow, and at significant speed.

And the whole point of a gravity turn is to point the pointy end exactly towards the airflow at all times apart from the very start of the turn.

If you do the gravity turn right, there is virtually no difference between prograde in surface mode and prograde in orbital mode by the time you get to the altitude that the switch occurs.

Edited by Plusck
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@Reactordrone's advice about fins and drag are spot-on. Especially the bit about the draggy top.

As it is now, you have a significant amount of drag between the core nose-cone and the part underneath it (flat rear-facing surfaces are actually a tiny bit worse for drag than an equivalent forward-facing flat surface), then three radiators (I'm not sure they are needed, here, and radiators don't help much for re-entry heating except to smooth out heat spikes for delicate parts). You would be far better off with just the mk1 pod with a parachute on top and the heatshield underneath it, followed by the decoupler.

In the pics, you're turning 45° to the airflow at 1,000 mph (470m/s), at 12km altitude. If you have any sort of lateral surface area (and you have lots) and any significant distance between a draggy front end and the CoM (a torque lever arm) that is not going to end well.

6 hours ago, KillaJake99 said:

I haven't unlocked the struts yet then.

And from what I've experienced, using the Hexagonal snapping and lining them up to be in a straight line allows for sturdier builds. Like if I wanted to attach a large booster, or a set of fuel tanks attached to an engine, and I used multiple radial decouplers aligned in a straight line, it stabilized previously unstable long rockets.

If there is any benefit to using multiple decouplers, it's because the parts are clipping into one another. The parts are not considered to be "connected" until the game actually constructs the craft, then it notices that the parts are clipped and applies a "sort-of-attached" effect.

To be honest, I have no idea how strong clipping effects are. I'm sure spaceplane builders (i.e. not me, really) have a better idea since any advanced plane design tends to involving significant clipping of wing parts amongst themselves and with the fuselage.

Still, if it works for you, then that's great, but as soon as you get struts you should (imho) avoid the practice and switch to struts instead.

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2 hours ago, Plusck said:

 If you go straight up to 40km and then turn east, you are turning your rocket sideways to the airflow, and at significant speed.

 

But if you go straight up to 70km and then turn east, you are guaranteed the absolute minimum aerodynamic drag of all, because you are precisely prograde the entire way.

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2 hours ago, bewing said:

But if you go straight up to 70km and then turn east, you are guaranteed the absolute minimum aerodynamic drag of all, because you are precisely prograde the entire way.

Well yes, obviously, since you are now in space and you went through the minimum amount of atmosphere to get there.  However that is not what OP is doing and not what was being discussed (turning at 40km) or what was shown in the pics (turning at 12km), and is not an efficient way of getting to orbit.

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7 hours ago, Plusck said:

In the pics, you're turning 45° to the airflow at 1,000 mph (470m/s), at 12km altitude. If you have any sort of lateral surface area (and you have lots) and any significant distance between a draggy front end and the CoM (a torque lever arm) that is not going to end well.

Pretty much this.  With fins high on the craft (i.e., above the center of mass), any airflow hitting them from the side will tend to push the nose further away from prograde.  And with a radical turn at low altitude/high speed (a description that fits the pics you posted), you get a lot of airflow hitting them from the side. That's why you generally want fins at the far back end, and you generally want to stay pointed close to prograde (i.e., within the ring of the prograde marker) while you're in atmosphere.

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On 7/8/2016 at 9:20 PM, KillaJake99 said:

Thank you, especially to bewing on the last post with the number of helpful tips.

For anyone who wanted photos, they are up on my imgur under the album name "KSP Issues"

General Link: http://killajake99.imgur.com/

Direct Album link: http://imgur.com/a/pM8q0

They should work, but please let me know if you encounter any issues when attempting to access them.

Okay, after some earlier posts I thought you were having issues that weren't the standard "why does this flip out" ones. But after seeing the pictures, I would say you are very much having the same rocket-flipping-out problems that everybody, including all of us other posters here, have had.

Your rocket is very short, and as others have said, your control wings are located at best very near the center of mass, so they have very little lever arm to work with and won't provide much moment even when they're working right. Your second stage needs to be longer and the fins need to be about as far back as you can put them.

Also, are those Reliants? If so, you have no real control authority. As noted above, the fins are too close to the center of mass to do anything, and the reaction wheels are not nearly strong enough to correct even the slightest aerodynamically-induced flipout. The only other effective source of control is a gimballed engine, like a Swivel. Once you get high enough the fins won't be effective, so you need the gimbal for that regime anyway.

In addition...you have brought way too much boom to this party. The fifth picture shows you going 415 m/s at roughly 5 km, the densest part of the atmosphere. Keep in mind Mach 1 is at around 340 m/s; those white effects you see indicate Mach effects and shock drag. Once you get Mach effects, drag becomes much more pronounced and that whole draggy-bits-in-front stuff becomes way more important. In the old drag model, high TWR was the name of the game to get out of the souposphere quickly, but in the new one anything above TWR of 1.5 is asking for trouble. If I'm not mistaken, this kind of TWR will get you into Mach territory in the 12-15 km range where the atmosphere is much thinner. Once you get above about 33 km you're pretty much in space and you can turn with impunity, but by that point you should be going very fast already with a large horizontal component to your velocity.

What I would suggest is 1) remove two of those side boosters 2) lengthen the second stage by adding fuel to make up for the dV you take out by removing those boosters 3) move those fins way way back, possibly onto the boosters instead of the second stage 4) switch the second stage motor (if not all of them) to a Swivel.

If it makes you feel any better, going way back to your original post: this was not a problem with not understanding how the controls work - you understood perfectly well. It's just that aerodynamics is grabbing your rocket and shaking it like a dog with a slobbery rope toy, and your rocket currently has no ability to overcome those forces. But like I said, we've all been through that, and you will too. I look forward to seeing what you come up with.

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       If you are using reliants, you have almost no control authority other than the pod torque, and from what you said, the pod runs out of battery.

        Use swivels or terriers on the upper stages, and use batteries, as thrust vectoring is useless if you aren't thrusting.

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On 7/8/2016 at 3:20 PM, KillaJake99 said:

Thanks again for the advice. I didn't actually mean to select those contracts, I thought they said below x altitude, and I didn't want to cancel them because of the penalty to my funds.

Also, I kept turning caps off because I didn't know what it did and I just thought I kept accidentally pressing it,  and I could tell it was on because it has an on/off LED on the key. Maybe that will help. Thank you

You can alt-F12 to open debug menu, go to the contracts tab (near the right I think) and hit the complete button (labeled com) and it will treat it as if you completed it, so you don't lose reputation or money. It's kinda like a money cheat as well. Find a tastey high paying contract, accept it and complete it. If anything it's good for those accidentally accepted contracts. 

But nothing is better than overcoming adversity and owning that contract. More important than money and reputation in early career is personal experience. 

Edited by jedensuscg
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With the control modifications the ship is orbit capable so if you do the polar orbit with the periapsis just inside the 70km mark as Zophos suggested you should be able to hit all of the contract points with very little battery use. Once in orbit the reliant's alternator will have charged up your batteries and when you power down the stability control your battery won't drain. That should leave you enough power to manoeuvre for orbital boosts and the de-orbit burn.

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5 hours ago, EnderKid2 said:

*batteries for the pod torque*

He should not be having energy problems unless he's [trying to] turning excessively while he's not under thrust, because the alternators on the engines will keep up. But you have to be thrusting through most of the atmosphere, so lower TWR and a loger burn helps immensely.

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Yep, as others have pointed out, the problem is the design of your rocket. The center of pressure is almost certainly above the center of mass and that is a surefire way to guarantee you will not go to space.

Try playing in sandbox mode for a bit and construct a rocket that looks like the following:  http://imgur.com/UhQKGYS

That engine is the LT45 "swivel" which is a gimbaling engine that will help you maneuver. The similar looking LT30 does not gimbal and is not what you want.

Note how the center of lift (blue orb) is far below the center of mass (yellow orb). This is what you want in your own designs.

Anyway, try flying this rocket for a while until you get used to the controls. Don't try to turn much until your speed is > 100m/s.  Throttle back as you climb and burn off fuel and try to keep your acceleration < 3g's or so. 

With a little practice, soon everything about flying will become second nature.

Good luck!

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